Messages in this thread Patch in this message |  | | | From | "Srivatsa S. Bhat" <> | | Subject | [PATCH v2 1/4] PM/Freezer: Use thaw_kernel_threads() in preparation for changes to thaw_processes() | | Date | Tue, 31 Jan 2012 04:44:30 +0530 |
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As of now, thaw_processes() is a superset of thaw_kernel_threads() in the sense that thaw_processes() thaws both userspace tasks and kernel threads. But that is going to change very soon. So, in preparation for that, add some calls to thaw_kernel_threads() like this:
* If only kernel threads need to be thawed, _replace_ thaw_processes() with thaw_kernel_threads().
* If everything needs to be thawed, _add_ a call to thaw_kernel_threads() adjacent to the existing call to thaw_processes().
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> --- kernel/power/hibernate.c | 5 +++++ kernel/power/power.h | 15 +++++++++++++-- kernel/power/process.c | 4 ++-- kernel/power/user.c | 8 ++++++++ 4 files changed, 28 insertions(+), 4 deletions(-) diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index a5d4cf0..1670387 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -656,6 +656,11 @@ int hibernate(void) } Thaw: + /* + * Kernel threads had been frozen inside hibernation_snapshot(). + * So thaw them here, on the success path. + */ + thaw_kernel_threads(); thaw_processes(); Finish: free_basic_memory_bitmaps(); diff --git a/kernel/power/power.h b/kernel/power/power.h index 0c4defe..e37a1e0 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -231,12 +231,23 @@ extern int pm_test_level; #ifdef CONFIG_SUSPEND_FREEZER static inline int suspend_freeze_processes(void) { - int error = freeze_processes(); - return error ? : freeze_kernel_threads(); + int error; + + error = freeze_processes(); + if (error) + goto Finish; + + error = freeze_kernel_threads(); + if (error) + thaw_processes(); + +Finish: + return error; } static inline void suspend_thaw_processes(void) { + thaw_kernel_threads(); thaw_processes(); } #else diff --git a/kernel/power/process.c b/kernel/power/process.c index eeca003..3734fb9 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -143,7 +143,7 @@ int freeze_processes(void) /** * freeze_kernel_threads - Make freezable kernel threads go to the refrigerator. * - * On success, returns 0. On failure, -errno and system is fully thawed. + * On success, returns 0. On failure, -errno and all kernel threads are thawed. */ int freeze_kernel_threads(void) { @@ -159,7 +159,7 @@ int freeze_kernel_threads(void) BUG_ON(in_atomic()); if (error) - thaw_processes(); + thaw_kernel_threads(); return error; } diff --git a/kernel/power/user.c b/kernel/power/user.c index 3e10007..eaf5c97 100644 --- a/kernel/power/user.c +++ b/kernel/power/user.c @@ -119,6 +119,7 @@ static int snapshot_release(struct inode *inode, struct file *filp) free_all_swap_pages(data->swap); if (data->frozen) { pm_restore_gfp_mask(); + thaw_kernel_threads(); thaw_processes(); } pm_notifier_call_chain(data->mode == O_RDONLY ? @@ -237,6 +238,13 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd, if (!data->frozen || data->ready) break; pm_restore_gfp_mask(); + + /* + * Be paranoid and thaw kernel threads as well, in order to + * make sure that the system gets thawed fully, irrespective + * of which (error) path we took to come here. + */ + thaw_kernel_threads(); thaw_processes(); usermodehelper_enable(); data->frozen = 0;
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